Existing ultrasonic imaging systems have limitations upon resolution that restrict their usefulness in identifying fine detail. These limitations arise both from limited axial resolution on the Z(depth) axis due to focusing limitations, and lateral resolution on the X and Y axes due to limitations upon the number of elements it is feasible to include in an array of imaging transducers, or the rate at which such transducers can be scanned. Axial resolution limitations can to some extent be bypassed by temporal filtering based on transit time, but lateral resolution restrictions have proved more intractable.
It is an object of the present invention to provide an ultrasonic imaging system which addresses these problems.